My friends grandmother had executed a will by dividing her property among her 4 sons & 3 daughters & herself. All the three daughter were married. The 4 sons without informing their 3 sisters got registered & entered their names in the property of the grandmother after her death. The 3 daughters were unware about this. Now after 10 years elapsed they came to know about the fact & were aggrieved. What step can they take for claiming their part of right. whether the will is valid. what is the time limitation. please let me know.